Roller pen



FIG. 1 is a top left perspective view of a roller pen according to the new design;

FIG. 2 is a left elevation view thereof;

FIG. 3 is a right elevation view thereof;

FIG. 4 is a front elevation view thereof;

FIG. 5 is a rear elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken line showing of the elements of the roller pen is for the purpose of illustrating portions of the roller pen that form no part of the claimed design. 

The design for a roller pen, as shown and described. 